System and Methods for Making Bioproducts

ABSTRACT

Processes for continuous preparation of bioproducts are described herein. The processes include contacting fatty acid glycerides with alcohols in the presence of an acidic heterogeneous catalyst and separating the fatty acid alkyl esters from the reaction products.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/518,559, filed Oct. 20, 2014, which is a continuation of U.S. patentapplication Ser. No. 13/414,484 filed Mar. 7, 2012, which claims thepriority benefit of U.S. Provisional Patent Application Ser. No.61/451,037, filed Mar. 9, 2011; and also claims the priority benefit ofU.S. Provisional Patent Application Ser. No. 61/451,040, filed Mar. 9,2011 and also claims the priority benefit of U.S. Provisional PatentApplication Ser. No. 61/451,043, filed Mar. 9, 2011, whose disclosuresare incorporated herein by reference in their entirety.

BACKGROUND Field of the Invention

The present invention relates to a process for making esters. Moreparticularly, it relates to a continuous process for making fatty acidalkyl esters.

Brief Description of Related Art

Biobased products (for example, biodiesel and/or biolubricants)typically include long chain, fatty acid alkyl esters produced fromvegetable oils or animal fats by transesterification of the fatty acidglycerides with alcohols. Biodiesel typically include long chain, fattyacid alkyl esters produced from vegetable oils or animal fats bytransesterification of the fatty acid glycerides with lower alcohols(for example, methanol and/or ethanol). Biolubricants may be preparedthrough transesterification of glycerides with alcohols having carbonnumbers ranging from 5 to 12 or greater, branched alcohols of similarmolecular weight, or transesterification of fatty acid methyl esters.Due to environmental concerns bio-based products in many formulationsare being used as substitutes for the petroleum-based products. Biobasedproducts derived from vegetable and plant products, such as soybean,sunflower, and rapeseed etc., are renewable, biodegradable, lessenvironmentally hazardous, and safer to handle. Similarly, otherrenewable sources of fatty acid glycerides include rendered animal fatsand waste cooking oils from commercial food production. Rendered animalfats and waste cooking oils may also be used in the production ofbiodiesel fuels and biolubricants for automobile applications,mechanical engine applications, cosmetic applications, and soaps.

The heating value of vegetable oil is similar to that of fossil fuel(for example, diesel), but the direct use of vegetable oils in thediesel engines is limited by some of their physical properties. Forexample, the viscosity of vegetable oil is about 10 times the viscosityof diesel fuel.

Transesterification of fatty acid glycerides may be used to improve thefuel value and lubricant utility of the fatty acid glycerides. Theproduction of useful industrial compounds from naturally-derived andsustainably-produced fatty acid glycerides is made difficult by thepresence of lipophilic or oil soluble material which must be removed topermit the following transesterification to reach a high level ofconversion and economic efficiency. Such problems with seed oils includedegumming, the removal of phospholipids; deodorizing, the removal offree fatty acids; and bleaching, the removal of finely divided solidsand colored materials. Conventional processes that use alkalinecatalysts for the production of fatty acid methyl esters may be highlysensitive to the presence of contaminates in the fatty acid glyceridephase.

Moisture may deactivate the alkaline catalyst. Free fatty acids presentin the starting material may inactivate the alkaline catalyst andproduce soaps; and unsaponifiable materials may react with suchcatalysts. Water and/or soaps interfere with the separation of glycerinfrom the fatty acid alkyl ester mixtures. Additionally, the finalproduct may have to be blended with other oils to adjust the free fattyacid content and/or reduce the content of contaminants in the finalproduct.

Conventional means for recovering valuable glycerin fromnaturally-derived and sustainably-produced fatty acid glyceridesinvolves saponification of the fatty acid glyceride which affords acrude glycerin product in an aqueous mixture. The crude mixture may ormay not include salts and other undesirable materials, requiringexpensive dewatering and further refinement.

Processes for the transesterification of fatty alkyl esters usingheterogeneous catalysts have been developed. Many of the processesrequire separation of the catalyst from the system and/or furtherprocessing to remove glycerin and/or other by-products of thetransesterification process.

U.S. Pat. No. 7,754,643 to Srinivas et al., which is incorporated hereinby reference, describes a catalyst and method of use for thetransesterification of glycerides, fatty acid esters and cycliccarbonates.

U.S. Pat. No. 7,482,480 to Srinivas et al., which is incorporated hereinby reference, describes a process for the preparation of hydrocarbonfuel that includes contacting fatty acid glycerides with alcohols in thepresence of a solid, double metal cyanide catalyst at a temperature inthe range of 150° to 200° C. for a period of 2-6 hrs and separating thecatalyst from the above said reaction mixture to obtain the desiredhydrocarbon fuel.

U.S. Pat. No. 7,842,653 to Darbha et al. describes a batch process forthe preparation of lubricants from vegetable oil or fat obtained fromanimal source that involves a reaction of vegetable oil or fat with analcohol in the presence of a double metal cyanide catalyst, at atemperature in the range of 150° to 200° C. for a period of 3 to 6 hrsto obtain the desired biolubricant.

International Application Publication No. WO/2009/113079 to Srinivas etal., which is incorporated herein by reference, describes a process forthe preparation of biofuels or biofuel additives from glycerol.

U.S. Pat. No. 8,124,801 to Srinivas et al., which is incorporated hereinby reference, describes a batch process for the preparation of fattyacid alkyl esters using a catalyst that includes a metal from Group VIBof the Periodic Table, a metal from Group IIIA of the Periodic Table andan element group VA of the Periodic Table.

U.S. Patent Application Publication no. 2010/0108523 to Sams et al.,which is incorporated herein by reference, describes removal of glycerinfrom biodiesel using an electrostatic process.

U.S. Pat. No. 7,531,688 to Fleischer, which is incorporated herein byreference, a method for making fatty acid alkyl esters by reacting fattyacid glycerides with an excess of alcohol in a pressurized environment,where the unreacted alcohol component is separated from the reactionproduct by a flash purification techniques.

Conventional processing (for example, batch processing) to prepare fattyacid alkyl esters, removal of excess alcohols and other volatilecompounds is done by reducing a pressure of the reaction vessel anddistilling or flashing the excess alcohol from the reaction vessel untilall or substantially all of the alcohol is removed from the reactionvessel, which may cause prolonged heating of the reaction mixture in thepresence of the alcohol. Prolonged heating of the reaction product maycause thermal degradation of the fatty acid alkyl esters and/orhydrolysis of the fatty acid alkyl esters. Thus, an efficient method ofremoving alcohols and/or water from the reaction mixture is highlydesired.

As described, many methods and/or catalysts for the transesterificationof fatty alkyl acids have been proposed, however, many methods requirepurification of starting materials, removal of water from the startingfatty alkyl acid, and/or steps to remove by-products formed from theesterification reactions. Hence, an efficient method of transesterifyingboth edible and non-edible vegetable oils in refined or unrefined formsat mild conditions is highly desirable. Moreover, an efficient method ofsimultaneously converting free fatty acid contaminants ofnaturally-derived and sustainably-produced fatty acid glycerides at mildconditions is highly desirable. Such combined methods enable economicbenefits and make the bioproducts an economical alternative to petroleumbased diesel and lubricants.

SUMMARY

Embodiments described herein describe systems and methods for producingfatty acid alkyl esters.

In some embodiments, a method of continuously making fatty acid alkylesters includes determining a flow rate of a feedstock stream, whereinthe feedstock stream comprises one or more fatty acid glycerides;contacting the feedstock stream and an alcohol stream with aheterogeneous acidic catalyst to produce a reaction mixture streamhaving a predetermined flow rate from the reactor, wherein the reactionmixture stream comprises unreacted alcohol, one or more fatty acid alkylesters, and glycerin; and separating substantial portion of theunreacted alcohol while cooling a portion of the reaction mixture.

In some embodiments, a system of continuous manufacture of fatty acidalkyl esters includes at least one mixing device for mixing one or morealcohol compounds and one or more feedstocks, wherein the feedstockcomprises one or more fatty acid glycerides and one or more free fattyacids; a reactor, the reactor being capable of receiving a flow from themixing device, wherein, during use, allows contact of the flow with aheterogeneous acidic catalyst; a device coupled to the reactor, whereinthe device receives flow from the reactor and allows a sudden drop inpressure to induce removal of one or more volatile compounds from thereaction mixture exiting the reactor while maintaining a desiredpressure of the reactor, wherein the reaction mixture comprises one ormore of the alcohol compounds, one or more fatty acid alkyl esters,glycerin, or mixtures thereof; and a separator coupled to the device,the separator capable of receiving flow from the device, separating atleast one alcohol compound from the reaction mixture, and cooling aportion of the reaction mixture.

In some embodiments, a system of continuous manufacture of fatty acidalkyl esters includes at least one mixing device for mixing one or morealcohol compounds and one or more feedstocks, a reactor, the reactorbeing capable of receiving a flow from the mixing device, at least oneanalyzer coupled to the reactor, a device coupled to the reactor; and aseparator coupled to the device, the separator capable of separating theglycerin from the one or more fatty acid alkyl esters using anelectrostatic field. The analyzer measures concentrations of thereaction mixture in the reactor. The device allows a sudden drop inpressure to induce removal of one or more of the alcohol compoundsand/or water from the reaction mixture.

In some embodiments, a method of continuous manufacture of fatty acidalkyl esters includes, assessing a total amount of fatty acid glyceridesand/or a total amount of alcohol in a fatty acid glyceride/alcoholfeedstock stream, determining a flow rate of the fatty acidglyceride/alcohol feedstock stream; contacting at least a portion of thefatty acid glyceride/alcohol feedstock stream with one or morecatalysts, obtaining an analysis of a reaction mixture formed fromcontact of the fatty acid glyceride/alcohol feedstock stream with atleast one of the catalysts, assessing a concentration of at least thefatty acid glycerides, at least one of the fatty acid alkyl esters, orglycerin from at least one of the obtained analyses, and adjusting oneor more contacting conditions based on at least one of the assessedconcentrations. The flow rate of the feedstock stream may be based onthe assessed amount of fatty acid glycerides and/or assessed amount ofalcohol in the fatty acid glyceride/alcohol feedstock stream.

In some embodiments, a method of making one or more bioproducts usingquality control includes collecting data from one or more continuousprocesses to produce one or more bioproducts, wherein the data setincludes a) conversion data for one or more feedstocks to fatty acidmethyl esters, b) catalyst aging, c) feedstock selection, d) reactionproduct composition, e) by-product composition, f) quality of at leastone of the bioproducts, or g) combinations thereof, wherein the at leastone of the feedstocks comprise one or more fatty acid glycerides and/orone or more alcohol; and adjusting one or more parameters of thecontinuous process based on the collected data to maintain or adjust aquality of at least one of the bioproducts produced.

In some embodiments, a method of making bioproducts, includesdetermining a flow rate of a feedstock stream, contacting the feedstockstream and an alcohol stream with a heterogeneous acidic catalyst toproduce a reaction mixture stream having a predetermined flow rate, andadjusting a temperature and a pressure of the reaction mixture streamsuch that an alcohol stream separates from the reaction mixture at arate sufficient to remove a majority of the alcohol and water whileinhibiting hydrolysis of the fatty acid alkyl ester products.

In some embodiments, a method of making one or more bioproducts,includes determining a flow rate of a feedstock stream having a watercontent of greater than 2 percent by weight, contacting at least aportion of the wet feedstock with a catalyst in the presence of one ormore alcohols to produce a reaction mixture, separating a fatty acidalkyl esters/glycerin stream from the reaction mixture, and applying anelectrostatic field to fatty acid alkyl esters/glycerin stream such thatan fatty acid alkyl esters stream separates from the fatty acid alkylesters/glycerin stream. The fatty acid alkyl esters/glycerin streamhaving a water content of at most 2 percent by weight.

In some embodiments, a method of making one or more bioproducts includesassessing an amount of free fatty acids in a feedstock stream,determining a flow rate of the feedstock stream, determining a flow rateof an alcohol stream, contacting at least a portion of the feedstockstream and the alcohol stream with a heterogeneous acidic catalyst toproduce a reaction mixture stream; and separating a fatty acid alkylesters stream from the reaction mixture stream. The flow rate of thealcohol stream may be determined based on a predetermined mole ratio ofalcohol to free fatty acid.

In some embodiments, a method of making one or more bioproducts,includes determining a flow rate of a feedstock stream that includes oneor more fatty acid glycerides; determining a flow rate of an alcoholstream comprising one or more alcohols, contacting at least a portion ofthe feedstock stream with a heterogeneous acidic catalyst in thepresence of the alcohol stream to produce a reaction mixture stream, andseparating a fatty acid alkyl esters stream from the reaction mixturestream. The flow rate of the alcohol stream may be determined based on apredetermined mass ratio of total alcohols to total fatty acidglycerides in the feedstock stream.

In some embodiments, a method of making biodiesel and biolubricants,includes contacting at least a portion of a feedstock with aheterogeneous acidic catalyst to produce a first mixture, separating afatty acid methyl ester/glycerin stream from the reaction mixture,applying an electrostatic field to the fatty acid methyl ester/glycerinstream such that an fatty acid methyl ester stream separates from thefatty acid methyl ester/glycerin stream, contacting the fatty acidmethyl ester stream with an additional heterogeneous acidic catalyst inthe presence of a stream that includes one or more alcohols or polyolsto produce a second mixture, and separating one or more fatty acid alkylesters from the second mixture. At least one of the alcohols or polyolshas a carbon number greater than 5 and at least one of the fatty acidalkyl esters includes an alkyl group having a carbon number of at least5.

In some embodiments, a method of making omega 3 and omega 6 fatty acidsincludes contacting a feedstock rich in polyunsaturated fatty acids witha heterogeneous acidic catalyst in the presence of one or more alcoholsto produce a reaction mixture, and separating at least one or more ofthe polyunsaturated fatty acids from the reaction mixture. The one ormore polyunsaturated fatty acids may include an omega 3 and/or an omega6 fatty acid.

In some embodiments, the feedstock includes one or more fatty acidglycerides, one or more free fatty acids, a stream that includesmethanol and a stream that includes fatty acid glycerides, orcombinations thereof. The fatty acid glycerides stream may contain atleast 20 percent by weight free fatty acids. In some embodiments, thefeedstock includes one or more fatty acid glycerides and a predeterminedamount of one or more polyunsaturated fatty acids. In some embodiments,at least one of the catalysts may include an acidic heterogeneouscatalyst. In some embodiments, the reaction mixture may include one ormore compounds of the feedstock unreacted fatty acid glycerides, one ormore fatty acid alkyl esters, glycerin, unreacted alcohols, or mixturesthereof.

In further embodiments, features from specific embodiments may becombined with features from other embodiments. For example, featuresfrom one embodiment may be combined with features from any of the otherembodiments. In further embodiments, bioproducts are produced using anyof the methods and/or systems described herein. In further embodiments,additional features may be added to the specific embodiments describedherein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates one exemplary embodiment of a continuous process forproducing fatty acid alkyl esters.

FIG. 2 illustrates one exemplary embodiment of a continuous process forproducing fatty acid alkyl esters.

FIG. 3 illustrates one exemplary embodiment of a continuous process forproducing fatty acid alkyl esters.

DETAILED DESCRIPTION

Embodiments of methods described herein provide an efficient process formanufacturing of fatty acid alkyl esters in high yields at mildconditions. Such a fatty acid alkyl ester may be used as a biofuel, forexample, biodiesel, or used as a biolubricant. In some embodiments, themethod is a continuous process for the production of biodiesel andbiolubricants from fatty acid glycerides containing significant amountof free fatty acids and/or water. The process is atom-efficient andmoderate reaction conditions (for example, temperature and pressure) areemployed. Unlike conventional methods, the methods described herein aremore efficient even with non-edible oil containing free fatty acids andwater impurity in oil. Thus, there are few to no limitations on thequality of oil that may be used.

Minimally refined naturally occurring or sustainably-produced fatty acidglycerides may be converted into fatty acid alkyl ester mixtures withhigh efficiency. Such minimal processing may include among otherinexpensive processes such as the filtration of insoluble materials ordecantation of gross amounts of water. Further, unlike conventionalalkaline or other solid acid catalyzed processes, free fatty acids areconverted into alkyl fatty acid esters with high efficiency and fattyacid glycerides are also converted into alkyl fatty acid esters, also inhigh efficiency in one step.

Utilizing a continuous process to produce alkyl fatty acid esters allowsautomation to be incorporated into overall process. Automation may beused to regulate quantities and perform assays on a continuous basis,thus better production economics and greater asset utilization arerealized. Using a continuous process improves product consistencies ascompared to a batch process, thus, quantities of high quality productsare produced.

In some embodiments, a continuous process may include use of one or moreanalyzers to determine quantities and/or qualities of fatty acidglyceride feedstocks and/or alcohol streams used in the continuousprocess. Examples of analyzers include, but are not limited to, nearinfrared spectrometers, liquid chromatographs, gas chromatographs, massspectrometers, nuclear magnetic resonance spectrometers or combinationsthereof. In some embodiments, one or more analyzers are coupled to oneor more units of the continuous process. The analyzer may be an infraredfiber-optic probe or a flow cell coupled to one or more units.

Continuous flow through a reactor allows for “real time” reactionmonitoring of the reaction mixture, thus reaction times may beminimized. Monitoring the reaction allows for adjustment of reactionconditions such that by-products of the transesterification reaction areminimized. Reaction conditions include, but are not limited to, flowrate, temperature, pressure, mass ratios (alcohol to feedstock) orcombinations thereof. Monitoring of the reaction mixture may includeassessing the amount of product produced, assessing the amount of one ormore starting materials, and/or assessing an amount of by-products inthe reaction mixture. For example, the appearance of product peaksand/or the absence of starting material may be monitored. The reactionmay be monitored using spectrometry techniques (for example, nearinfrared, nuclear magnetic resonance), chromatographic techniques (forexample, gas chromatography and/or liquid chromatography). In someembodiments, near infrared spectrometry is used to monitor the progressof the reaction in reactor 110.

Monitoring may be performed using off-line and/or in-line analyses.“Off-line analysis” refers obtaining an analysis using an instrument notdirectly coupled to the system. For example, a sample may be obtained atthe inlet of a reactor and analyzed using an instrument at a locationaway from the reactor. “In-line sampling” refers to obtaining ananalysis using an instrument and/or other analysis instrumentationdirectly coupled to the continuous system. For example, a near infraredspectrometer may be coupled to a reactor and/or one or more conduits ofthe system.

Obtaining an analysis may include development of calibration curves. Forexample, calibration curves may be established for water content inmethanol and/or the fatty acid glyceride feedstock, unsaponifiablematerials in the glyceride feedstock, and products in a reactionmixture. Comparison of reagents and/or reaction products to thecalibration curves enhances product consistency and production of higherquality materials as compared to batch processing.

In some embodiments, the quality of the reagents and/or startingmaterials is assessed. For example, water content and content ofcompounds that are unsaponifiable (for example, compounds that cannot beconverted to soaps) of the fatty acid glyceride feedstock. Methanol maybe assayed (for example, assayed using near infrared spectrometry) todetermine the amount of water in the methanol. In some embodiments, thefatty acid glyceride feedstock/alcohol stream is monitored (for example,using near infrared analysis) to determine the mass ratio of the fattyacid glyceride feedstock to the alcohol. Based on the determined massratio, an amount of alcohol and/or fatty acid glyceride feedstock may beadjusted to meet a pre-determined mole ratio. In some embodiments, aflow rate of the fatty acid glyceride feedstock stream, the alcoholstream and/or the fatty acid glyceride feedstock/alcohol stream isdetermined based on the assessed amount of fatty acid glycerides,assessed amount of alcohol, and/or assessed amount of free fatty acidsin the feed streams and/or the reaction product streams.

In some embodiments, a continuous manufacture of bioproducts (forexample, fatty acid alkyl esters), assessing a total amount of fattyacid glycerides and/or a total amount of alcohol in a feedstock stream.The feedstock stream may include fatty acid glycerides and alcoholcompounds. The flow rate of the feedstock stream may be determined basedon the assessed amount of fatty acid glycerides and/or alcohol in thefeedstock stream. In some embodiments, a flow rate of the feedstockstream may be based on a predetermined mole ratio of alcohol to freefatty acid. In certain embodiments, a flow rate of the feedstock streammay be based on a predetermined mass ratio of alcohol to fatty acidglyceride. The feedstock stream may be contacted with and/or flowed overone or more acidic heterogeneous catalysts. An analysis of a reactionmixture stream formed from contact of the feedstock with at least one ofthe catalysts may be obtained after a period of time. The reactionmixture stream may include fatty acid glycerides, one or more fatty acidalkyl esters, glycerin, unreacted alcohols, or mixtures thereof. Aconcentration of at least the fatty acid glycerides, at least one of thefatty acid alkyl esters, or glycerin from may be assessed from at leastone of the obtained analysis. One or more contacting conditions may beadjusted based on at least one of the assessed concentrations.

In addition, the continuous process described herein uses no water andproduces very little in the way of waste products, and worker exposureto regulated materials (for example, methanol) is limited. Incomparison, conventional processing requires measuring and handlingsodium methoxide or sodium or potassium hydroxide and then, eitherhydrochloric acid or sulfuric acid for neutralization of catalyst. Thisleads to extensive water use to remove salts, soaps or otherpost-processing steps, which while eliminating direct use of waterdefers the water consumption to resin regeneration or other step toreuse the “dry wash” agent.

In a batch process or a continuous process using alkaline catalyst rapiddistillation of alcohols (for example, methanol) from a reaction mixturecontaining residual catalyst, fatty acid alkyl esters, methanol, wateris difficult due to the partitioning of the alcohol between thealcohol/water phase and the fatty acid alkyl ester/glycerin phases.Furthermore, use of an alkaline catalyst may allow soaps to form in thereaction mixture that, under reduced pressure distillation and/or flashdistillation, cause foaming in the reaction mixture. Creation of foammay entrain reaction products (for example, fatty acid alkyl esters) inthe alcohol and cause loss of product. Multiple distillation and/orseparation steps may be required to remove catalyst, alcohol, glycerinand/or to obtain fatty acid alkyl esters suitable for commercial use.

Use of an acidic heterogeneous catalyst in a batch process requiresseparation of the catalyst from the reaction mixture upon completion ofthe process to obtain fatty acid alkyl esters suitable for commercialuse and to recycle the catalyst. Separation of catalyst from thereaction mixture requires extra equipment and increased processing time,as well as additional equipment to recover and recycle the catalyst.Failure to recycle can lead to higher cost of production. Residualcatalyst remaining in the reaction mixture may promote hydrolysis of thefatty acid alkyl ester to fatty acids and alcohol, thus the purity ofthe product may be affected.

Using continuous separation (for example, flash distillation) ofalcohols, water and/or other volatile components from the reactionmixture in fully continuous process allows for removal of methanoland/or water from the reaction mixture such that hydrolysis of the fattyacid alkyl esters and/or thermal degradation of the fatty acid alkylester is inhibited or significantly reduced as compared to batchprocessing of the reaction mixture. Furthermore, use of a continuousprocess does not require separation of the catalyst from the reactionmixture prior to the removal of methanol, as the catalyst remains in thereactor 110 in a fixed bed or other suitable configuration.

In the some embodiments, using a continuous process allows recovery ofglycerin in an essentially anhydrous, highly pure liquid state andcontaining no salts. The separated alkyl fatty acids ester mixtures arerecovered as distilled liquids containing no or substantially no highboiling partially converted glycerides. The absence of high boilingpartially converted glycerides makes the alkyl fatty acid ester mixturesuitable for use as fuel without further purification as high boilingpartially converted glycerides are detrimental to fuels, causingproblems such as plugged fuel lines, blocked injectors and poorcombustion.

In some embodiments, bioproducts are produced through esterification offatty acids with alcohols. The esterification is performed at moderateconditions and shorter reaction times as compared to batch processingand/or other conventional processes. Biodiesel may be produced throughesterification of fatty acids with alcohols having carbon numbersranging from 1 to 4 (C₁ to C₄). Biolubricants may be produced bytransesterification of fatty acid alkyl esters or esterification offatty acids with alcohols or polyols having a carbon number ranging fromC₅ to C₁₂ or branched alcohols of similar molecular weight. In someembodiments, bioproducts are produced by esterification of fatty acidglycerides with of one or more alcohols using a heterogeneous acidiccatalyst. As used herein, “heterogeneous catalyst” refers to a catalystthat is in a different phase (for example, a solid catalyst describedherein) to other compounds (for example, liquid or vapor) when mixedtogether. The catalyst may be separated easily by removal from a fixedbed reactor or separated from a mixture by centrifugation or by simplefiltration and re-used.

In an embodiment, fatty acid glyceride feedstocks may be low qualityoils. The ability to use low quality as well as high quality fatty acidglycerides (for example, natural animal or plant oils) allowsbioproducts to be produced in areas where natural plant oils are notabundant. Fatty acid glyceride feedstocks include, but are not limitedto, fatty acid monoglycerides, fatty acid diglycerides and fatty acidtriglycerides obtained from raw, unrefined and partially-refined oils(for example, oils from plants and/or plant seeds), inedible andnon-food oils, algal oils, animal fats, waste cooking oils and mixturesthereof. Examples of fatty acid glyceride feedstocks include glyceridesderived from fatty acids and/or oils that include fatty acid glyceridesand free fatty acids. Examples of oils that may be used as fatty acidglyceride feedstocks include, but are not limited to, oils from plantseeds, camellia oil, coconut oil, palm oil, pennycress oil, meadowfoam(Limnanthes alba) oil, sunflower oil, soybean oil mustard oil, oliveoil, cotton seed oil, rapeseed oil, margarine oil, jojoba oil, Jatrophaoil, karanja oil, vegetable oil, animal fat, grease, waste cooking oil,or mixtures thereof. In some embodiments, a content of triglycerides ina fatty acid glyceride feedstock may range from 10% to 99.9% by weight,from about 30% to about 95% by weight, or from about 50% to about 90% byweight.

In some embodiments, the fatty acid glyceride feedstock may include from5 percent up to 100 percent, 10 percent to 80 percent, 15 percent to 60percent by weight or 20-50 percent by weight free fatty acids. The term“free fatty acid” generally refers to a long chain carboxylic acid witha long hydrocarbon chain (for example, a carbon number greater than 6).Examples of free fatty acids include, but are not limited to, saturatedfatty acids, unsaturated fatty acids and polyunsaturated fatty acids.

Examples of saturated fatty acids include, but are not limited to:hexanoic acid (caproic acid); octanoic acid (caprylic acid); decanoicacid (capric acid); dodecanoic acid (lauric acid); tridecanoic acid;tetradecanoic acid (myristic acid); pentadecanoic acid; hexadecanoicacid (palmitic acid); heptadecanoic acid (margaric acid); octadecanoicacid (stearic acid); eicosanoic acid (arachidic acid); docosanoic acid(behenic acid); tricosanoic acid; and tetracosanoic acid (lignocericacid).

Examples of monounsaturated fatty acids include, but are not limited to:9-tetradecenoic acid (myristoleic acid); 9-hexadecenoic acid(palmitoleic acid); 11-octadecenoic acid (vaccenic acid); 9-octadecenoic(oleic acid); 11-eicosenoic acid; 13-docosenoic acid (erucic acid);15-tetracosanoic acid (nervonic acid); 9-trans-hexadecenoic acid(palmitelaidic acid); 9-trans-octadecenoic acid (elaidic acid);8-eicosaenoic acid; and 5-eicosaenoic acid.

Examples of polyunsaturated fatty acids include, but are not limited toomega-3 polyunsaturated fatty acids, omega-6 polyunsaturated fattyacids; and conjugated polyunsaturated fatty acids. Examples of omega-3polyunsaturated fatty acids include, but are not limited to:9,12,15-octadecatrienoic acid (alpha-linolenic acid);6,9,12,15-octadecatetraenoic acid (stearidonic acid);11,14,17-eicosatrienoic acid (eicosatrienoic acid (ETA));8,11,14,17-eicsoatetraenoic acid (eicsoatetraenoic acid);5,8,11,14,17-eicosapentaenoic acid (eicosapentaenoic acid (EPA));7,10,13,16,19-docosapentaenoic acid (docosapentaenoic acid (DPA));4,7,10,13,16,19-docosahexaenoic acid (docosahexaenoic acid (DHA));6,9,12,15,18,21-tetracosahexaenoic acid (nisinic acid);9E,11Z,15E-octadeca-9,11,15-trienoic acid (rumelenic acid);9Z,11E,13E,15Z-octadeca-9,11,13,15-trienoic acid (α-parinaric acid); andall trans-octadeca-9,11,13,15-trienoic acid (β-parinaric acid). Examplesof omega-6 polyunsaturated fatty acids include, but are not limited to:9,12-octadecadienoic acid (linoleic acid); 6,9,12-octadecatrienoic acid(gamma-linolenic acid); 11,14-eicosadienoic acid (eicosadienoic acid);8,11,14-eicosatrienoic acid (homo-gamma-linolenic acid);5,8,11,14-eicosatetraenoic acid (arachidonic acid); 13,16-docosadienoicacid (docosadienoic acid); 7,10,13,16-docosatetraenoic acid (adrenicacid); 4,7,10,13,16-docosapentaenoic acid (docosapentaenoic acid);8E,10E,12Z-octadecatrienoic acid (calendic acid);9Z,11E-octadeca-9,11-dienoic; 8E,10E,12Z-octadecatrienoic acid(a-calendic acid); 8E,10E,12E-octadecatrienoic acid (β-calendic acid);8E,10Z,12E-octadecatrienoic acid (jacaric acid); and5Z,8Z,10E,12E,14Z-eicosanoic acid (bosseopentaenoic acid). Examples ofconjugated polyunsaturated fatty acids include, but are not limited to:9Z,11E-octadeca-9,11-dienoic acid (rumenic acid);10E,12Z-octadeca-9,11-dienoic acid; 8E,10E,12Z-octadecatrienoic acid(α-calendic acid); 8E, 10E,12E-octadecatrienoic acid (β-calendic acid);8E,10Z,12E-octadecatrienoic acid (jacaric acid);9E,11E,13Z-octadeca-9,11,13-trienoic acid (a-eleostearic acid);9E,11E,13E-octadeca-9,11,13-trienoic acid (β-eleostearic acid);9Z,11Z,13E-octadeca-9,11,13-trienoic acid (catalpic acid);9E,11Z,13E-octadeca-9,11,13-trienoic acid (punicic acid);9E,11Z,15E-octadeca-9,11,15-trienoic acid (rumelenic acid);9E,11Z,13Z,15E-octadeca-9,11,13,15-trienoic acid (α-parinaric acid); alltrans-octadeca-9,11,13,15-trienoic acid (β-parinaric acid); and5Z,8Z,10E,12E,14Z-eicosapentanoic acid (bosseopentaenoic acid).

A content of free fatty acid in the feedstock may be determined usingstandardized test methods (for example, ASTM Test Method D1585 or D664).In some embodiments, the fatty acid glyceride feedstock may include atleast 5 percent, at least 10 percent or at least 20 percent of animalfat (for example, beef tallow). In some embodiments, the fatty acidglyceride feedstock includes from about 20 percent to about 90 percent,from about 30 percent to about 80 percent, or from about 40 percent to70 percent free fatty acids. In one embodiment, the fatty acid glyceridecontains at least 90 percent free fatty acid. In some embodiments,substantially all of the free fatty acids and fatty acid glycerides inthe feedstock are converted to fatty acid alkyl esters in one step.Thus, the fatty acid content in fatty acid alkyl ester product does notneed to be adjusted prior to selling the fatty acid alkyl ester product.Use of feedstocks having free fatty acids eliminates the need topretreat the feedstock to remove free fatty acids for separateprocessing or to be sequentially processed to convert first free fattyacid to esters, followed by converting the fatty acid alky ester-fattyacid glyceride mixture to solely fatty acid alkyl esters. The ability touse feedstocks containing free fatty acids is a savings in both capitaland operating cost.

The fatty acid glyceride feedstock may contain a significant amount ofwater from prior processing. For example, the fatty acid glyceridefeedstock may contain at least 1 percent by weight of water. In someembodiments, a fatty acid glyceride feedstock may have a water contentranging from 1 to about 30 percent by weight, from about 2 to about 20percent by weight, or from 3 to about 5 percent by weight. Fatty acidglyceride feedstocks containing high amounts of water may separated intoa water phase and an oil phase. The water phase may be removed prior toprocessing the fatty acid glycerides feedstock. In some embodiments,removal of separated water is not necessary.

Alcohols used in the transesterification of the fatty acid glyceridefeedstock may have from 1 to 50, from 2 to 25, or from 3 to 12 carbonatoms. Alcohols include hydrocarbons having at least one hydroxy group.Examples of alcohols include primary alcohols, diols, triols andpolyols. In some embodiments, the alcohols are primary alcohols.Alcohols include, but are not limited to, methanol, ethanol, propanol,butanol, pentanol, octanol, 2-ethylhexanol, decanol, dodecanol,glycerin, glycols (for example, propylene glycol 1,2 and propyleneglycol 1,3,) neopentyl glycol, trimethylol propane, pentaerythritol ormixtures thereof.

In some embodiments, a molar ratio of total fatty acid glycerides toalcohol may range from about 1:6 to 1:50, from 1:10 to 1:40, or from1:20 to 1:30. In some embodiments, molar ratio of total fatty acidglycerides to methanol is greater than 1:12, for example a molar ratioof total fatty acid glyceride to methanol is 1:15. In an embodiment, amass ratio of methanol to total fatty acid glyceride ranges from about0.40 to about 1, from about 0.5 to about 0.9 or from about 0.5 to 0.8.As used herein, “total fatty acid glycerides” includes all glyceridefunctionality determined from all glycerides in the feedstock (forexample, monoglycerides, diglycerides, and triglycerides).

In some embodiments, molar ratio of total free fatty acid to alcohol mayrange from about 1:6 to 1:50, from 1:10 to 1:40, or from 1:20 to 1:30.In some embodiments, molar ratio of total free fatty acid to methanol isgreater than 1:12, for example a molar ratio of total free fatty acidsto methanol is 1:15. In an embodiment, a mass ratio of methanol to totalfree fatty acids ranges from about 0.40 to about 1, from about 0.5 toabout 0.9 or from about 0.5 to 0.8.

In certain embodiments, alcohols having 1 to 4 carbon atoms are reactedwith a fatty acid glyceride feedstock to form fatty acid alkyl esterssuitable for use as a biodiesel fuel. Biolubricants may be made byreaction of alcohols having 5 to 50 carbon atoms with the fatty acidglyceride or fatty acid alkyl ester feedstock. In an embodiment, thefatty acid alkyl ester made using the process described herein has 15 to70 carbon atoms is used as a biolubricant. In some embodiments, the molepercent conversion of fatty acid glycerides is 90 to 100 mol % and thebiodiesel/biolubricant selectivity is greater than 95%. Examples, offatty acid alkyl esters made by the process described herein include,but are not limited to, alkyl esters of myristic, palmitic, palmitoleic,stearic, oleic, linoleic, linolenic, arachidic acids, or mixturesthereof.

The processes described herein may use a catalyst that has the addedadvantages of low cost and more run time life. In some embodiments, thecatalyst is solid. In certain embodiments, the catalyst has acidicproperties. Examples of the catalyst having acidic properties andpreparation thereof are found in U.S. Pat. No. 8,124,801 to Srinivas etal.

In certain embodiments, catalyst includes one or more metals from GroupVIB of the Periodic Table. The Group VIB metals may be inorganic salts(for example, nitrates, sulfates), and/or oxides. In some embodiments,the Group VIB metal is molybdenum or molybdenum oxide. An amount ofGroup VIB metal, calculated as metal by weight of catalyst, may rangefrom about 0.01% to about 10%, from about 0.5% to 5%, or from 1% 5%Group VIB metal by weight of catalyst. An amount of Group VIB metaloxide may range from about 5% to about 20%, from about 8% to about 17%,or from about 10% to about 15% Group VIB metal oxide by weight ofcatalyst.

In some embodiments, the catalyst includes one or more metals from GroupVIB of the Periodic Table described herein and a promoter. The promotermay be one of more elements from Group VA of the Periodic Table, forexample, phosphorus or phosphorus compounds. In certain embodiments, theGroup VA element (promoter) is a phosphorus compound. In an embodiment,the Group VA element is present in the range of about 0.1% to about 7%,about 0.5% to about 5%, about 1% to about 3% by weight of the catalyst.

In some embodiments, the catalyst includes one or more metals from GroupVIB of the Periodic Table described herein, a co-promoter and/or apromoter. The co-promoter may include metals or compounds of metals fromGroup IA of the Periodic Table, Group IIA of the Periodic Table, GroupIIIB of the Periodic Table, Group VIII of the Periodic Table, ormixtures thereof. Examples of metals from Group IA, Group IIA, GroupIIIB, or Group VIII of the Periodic Table include, but are not limitedto, sodium, potassium, calcium, lanthanum, and nickel. An amount ofco-promoter in the catalyst may range from about 0.0001% to about 10%,about 0.005% to about 8% or 0.5% to about 5% by weight of catalyst. Insome embodiments, the catalyst may contain from about 0.05% to about6.5% calcium by weight of the catalyst. In some embodiments, thecatalyst may include from 0.0001% to about 7.8% sodium and/or potassiumby weight of the catalyst. In some embodiments, the catalyst may includefrom about 0.0001% to about 4.5% lanthanum by weight of catalyst. Insome embodiments, the catalyst may include from 0.0001% to about 5.5%nickel by weight of catalyst.

The Group VIB metals, Group VIB metal compounds, promoters,co-promoters, or mixtures thereof may be supported on one or more oxidesof one or more metals from Group IVB of the Periodic Table. Examples ofGroup IVB metal oxides (refractory oxides) include, but are not limitedto, alumina oxide and/or titanium oxide. The refractory inorganic oxidemay be of synthetic or natural origin and have a medium to a highsurface area, and a well-developed pore structure. In an embodiment,hydrated alumina, when used as a support material, results in a productwhere the morphology of the active materials is well maintained in theresulting catalyst composition.

The catalytic metals (for example, Group VIB metals) may be applied to aformed or unformed support by one of several methods known in the art.This is usually followed by forming, if necessary, and by calcinationsto convert the catalytic metal compounds to oxides. U.S. Pat. No.3,287,280 to Colgan et al. and U.S. Pat. No. 4,048,115 to O'Hara, bothof which are incorporated herein by reference describe methods for thepreparation of supported catalysts.

The intermediate support material of the catalyst may be prepared byeither a solid mixing method or by a solution addition and subsequentmixing method. In both cases, the precursor of the support material (forexample, alumina oxide) is well peptized with suitable mineral acid, forexample, nitric acid and acetic acid. In an embodiment, nitric acid inthe range of 1.0-10.0% of the support mass is used for peptization. Thesupport precursor may be any of the Group IIIA or IVA refractory metaloxides or their combinations. In an embodiment, the Group IIIA metaloxide is alumina. In certain embodiments, a Group IIIA metal oxide ispeptized with a mineral acid in the range of about 1% to about 10% orabout 2% to 8%, or about 3% to about 7% by weight of the supportmaterial. For example, alumina oxide is peptized with nitric acid. In anembodiment, blending of various precursors of these metal oxides isperformed to obtain suitable pore size distribution.

After peptization, active catalytic compounds, for example, metal oxidesprecursors of Group VIB, may be added along with the promoter selectedfrom Group VA of the Periodic Table and/or co-promoter. In someembodiments, the co-promoter is added prior to forming the catalyst (forexample, during extrusion), but before drying and/or calcination of thecatalyst. The composition of the active metal, for example, molybdenum,may be incorporated using impregnation, compounding, extruding trials,various combinations of the processes described herein, or methods knownin the art. A proper selection of appropriate preparation conditions maybe made using methods known in the art. In some embodiments, the activemetal precursor, the promoter precursor, and/or co-promoter may be addedeither as separate compounds or together as slurry. For example, themetal precursor and the promoter precursor may be combined by mixing twoaqueous solutions together. An appropriate morphology and texture of themetal components may be achieved by applying suitable methods andcombination of precursors. In an embodiment, the size and shape of thesupported systems were to optimize, for example, tuning geometricalsurface area. The surface area of the catalyst may range from 50 m²/g to300 m²/g.

The catalyst may have a pore volume ranging from 0.2 ml/g to 0.95 ml/g,or from 0.5 ml/g to 0.7 ml/g. Pore volume of samples may be determinedby filling the pore space to saturation by applying water. The quantityof water is determined by its volume added or the weight increase of thesample. The pore space can be filled by putting the quantitatively knownsample in excess water and the excess water is removed, and thesaturated catalyst samples were weighed again to determine the totalwater uptake.

In some embodiments, the catalyst composition resulting from the abovedescribed process may be directly shaped. Shaping includes extrusion,pelletizing, beading, and/or spray drying. In some embodiments, spraydrying or beading is generally used when the catalyst composition isused in slurry type reactor, fluidized beds, moving beds, expanded beds,or ebullating beds. For fixed bed applications, the catalyst compositionmay be extruded, pelletized or beaded. In fixed bed applications, priorto or during the shaping, any additives that facilitate the shaping maybe used.

The resulting catalyst composition or more suitably the catalystintermediate may be, after an optional drying step, be optionallycalcined. Calcinations temperatures may range from about 100° C. to 600°C. or from about 350° C. to 500° C. for a time varying from 0.5 to 48hours. In certain embodiments, the catalyst samples are calcined attemperatures ranging from 400° C. to 500° C. or from 500° C. to 700° C.

The resultant extrudates may be further loaded with active metals toobtain the desired active metal composition for the finished product.Such further loading is directly related to the desired metal loading,and the amount incorporated during or prior to the shaping stage of thematerial. For the same, various impregnation methods known in the artcan be applied. Either the wet impregnation or the incipientimpregnation may be used to load active metals. In an embodiment, thepore filling incipient impregnation method may be applied to load theGroup VIB metal oxides. The method employed also may affect the poresize distribution of the finished catalyst, and hence the performance ofthe product. The material is again to be further thermal treated for theactivation of the catalytic components.

In some embodiments, a double metal cyanide catalyst may be used aloneor in combination with the Group IVB metal oxide catalyst describedherein. One of metals of the double metal cyanide catalyst is Zn²⁺ whilethe other is Fe. Co-existence of Zn and Fe in the active site linkingthrough cyano bridges makes it efficient to transform feedstockscontaining fatty acids in a single step to fatty acid esters. Thecatalyst could be separated easily by centrifugation or by simplefiltration and reused. Double metal cyanide catalysts are described inU.S. Pat. No. 7,754,643 to Srinivas, U.S. Pat. No. 7,482,480 toSrinivas, U.S. Pat. No. 7,842,653 to Srinivas, which are incorporatedherein by reference. For example, a double metal cyanide catalyst may beused alone or in combination with a molybdenum metal catalyst containingphosphorus as a promoter.

The catalysts described herein are highly efficient and are easilyseparated from the products for further re-use. In contrast, prior artcatalysts may require treatment with mineral acid, alkali bases, andlipases which may increase costs of catalyst separation. The catalystdescribed herein is beneficial and leads to an economic and eco-friendlyprocess. Hence, the solid catalysts described herein are not onlyefficient but avoid the tedious process of catalyst recoverycharacteristic of the prior art processes. The present catalyst systemis efficient without using any additional solvent.

In batch processing to produce fatty acid alkyl esters, a fatty acidglyceride, an alcohol, and a solid catalyst are contacted to produce areaction mixture. The catalyst used in a batch process may be a finelypowdered catalyst. Although the catalyst may remain in a separate phase,or substantially separate phase from the fatty acid glyceride, alcoholand/or reaction products during contacting, the catalyst is separatedfrom the liquid reaction mixture prior to the removal of methanol and/orglycerin using separation techniques known in the art. For example,centrifugation followed by simple decantation. The resulting catalystfree liquid reaction mixture may be separated by removal of excessalcohol through distillation techniques. Removal of the alcohol allowsthe fatty acid methyl esters to separate from remaining products. Fattyacid methyl esters may be separated from the reaction mixture by gravityseparation or by contacting the reaction mixture with a non-polarsolvent. In some embodiments, the non-polar solvent is petroleum ether.

In contrast to a batch process, the continuous process is used toproduce bioproducts, as described herein, eliminates the need forcatalyst separation and/or the saponification step used in conventionalalkaline catalyst processes. The reaction may be conducted using minimalor substantially no solvent which reduces production of by-productsand/or reduces costs of the process as compared to conventionalprocessing. The process conditions allow for increased glycerol purityand fatty acid methyl ester yield as compared to products produced usingconventional alkaline catalyst processing. The process described hereinalso reduces the formation of undesirable by-products, for example,glycerol methyl ethers.

In some embodiments, a mixture of fatty acid glyceride feedstock andalcohol is provided continuously to a reactor designed to operate atmoderate temperatures and pressures. FIG. 1 is a schematicrepresentation of a continuous process of an embodiment to produce fattyacid alkyl esters. The fatty acid glyceride feedstock may be stored in apermanent or movable tank (for example, totes). The fatty acid glyceridefeedstock may be heated to enhance fluidity of the feedstock and reducethe risk of plugging lines with high melting feedstocks or feedstockmixtures, e.g. tallow. In some embodiments, the fatty acid glyceridefeedstock is stored a temperature ranging from about 50° C. to about 90°C. or from about 60° C. to about 80° C. In some embodiments, the fattyacid glyceride feedstock is filtered to remove particulate and/orinsoluble matter. The fatty acid glyceride feedstock may be analyzed toassess the amount of fatty acid glycerides, free fatty acids, and/orwater in the fatty acid glyceride feedstock (for example, using nearinfrared spectrometry and/or Karl Fischer analysis for water). Forexample, amounts of oleic acid and triolein may be assessed in a fattyacid glyceride feedstock stream. The flow rate may be determined on amass or molar ratio of the oleic acid to alcohol and/or triolein ratioto alcohol or a combination of the oleic acid and triolein to alcoholratios.

Fatty acid glyceride feedstock stream 100 may be blended with alcoholstream 102 prior to entering the reactor to form a fatty acidglyceride/alcohol mixture. A temperature of fatty acid glyceridefeedstock stream may range from 100° C. to 250° C. at a pressure fromabout 650 to about 750 psig (about 4.5 MPa to 5.2 MPa). In someembodiments, a temperature of fatty acid glyceride feedstock stream mayrange from 200° C. to 230° C. at a pressure from 650 to 880 psig (about4.5 MPa to about 6 MPa). A continuous s flow rate of fatty acidglyceride feedstock stream 100 may range from about 0.1 Weight HourlySpace Velocity (“WHSV”) to about 1 WHSV, from 0.3 to 0.8 WHSV, or from0.5 to 0.7 WHSV. A temperature of alcohol stream 102 may range from 75°C. to 85° C. at a pressure from 650 to 750 psig (about 4.5 MPa to about5.2 MPa). A flow rate of alcohol stream 102 may range from about 0.1WHSV to about 1 WHSV, from 0.3 to 0.8 WHSV, or from 0.5 to 0.7 WHSV.

As fatty acid glyceride feedstock stream 100 from fatty acid glyceridefeedstock storage unit 101 and alcohol stream 102 from alcohol storageunit 103 flow through mixer 104, the streams are mixed to form fattyacid glyceride feedstock/alcohol stream 106. In some embodiments, fattyacid glyceride feedstock/alcohol stream is an emulsion. Mixer 104 may beone or more in-line mixers or other known mixers. In some embodiments,the fatty acid glyceride feedstock and alcohol may be deliveredcontinuously to the reactor as separate streams. Fatty acid glyceridefeedstock/alcohol stream 106 may pass through heater 108 to raise thetemperature of the stream to a temperature proximate the reactiontemperature. For example, heater 108 may raise the temperature of fattyacid glyceride feedstock/alcohol stream 106 to about 220° C. at apressure of 700 psig (about 4.8 MPa).

Fatty acid glyceride feedstock/alcohol stream 106 may enter reactor 110and flow upward through the reactor. A flow rate of fatty acid glyceridefeedstock/alcohol stream 106 may range from about 0.0.1 WHSV to about1.0 WHSV, from 0.3 to 0.8 WHSV, or from 0.5 to 0.7 WHSV.

The flow rate of fatty acid glyceride feedstock/alcohol stream 106through reactor 110 may be determined based on the assessed amount offatty acid glycerides and/or alcohol in the fatty acid glyceridefeedstock/alcohol stream. In some embodiments, a flow rate of the fattyacid glyceride feedstock/alcohol stream is determined based on apredetermined mole ratio of alcohol to free fatty acid. Reactor 110 mayinclude over one or more heterogeneous catalysts. In some embodiments,the catalyst is a heterogeneous acidic catalyst. Contact of the feedstreams with the catalyst produces a crude product. The crude productincludes fatty acid alkyl esters, glycerin, water, unreacted glyceridesand excess alcohol.

In some embodiments, the catalyst is fixed in the reactor. For example,the reactor may be a fixed bed reactor, a continuously stirred tankreactor, fluidized bed reactor or an ebullating bed reactor. Otherdesigns to allow continuous flow of the fatty acid glyceride feedstockstream, alcohol stream, the fatty acid glyceride feedstock/alcoholstream or mixtures thereof over the catalyst and through the reactor maybe contemplated. In some embodiments, the catalyst may be activatedprior to introducing feedstocks into the reactor by introducing a heatedstream of dry inert gas (for example, nitrogen) into the contactingzones at a known space velocity (SV=vol N₂/hr divided by vol ofcatalyst) at atmospheric pressure. For example, a catalyst may be placedin a reactor heated with a dry nitrogen stream at a space velocity of500/hr at atmospheric pressure. Activating the catalyst may involveheating the reactor contents to remove residual water, which promoteshydrolysis. In some embodiments, the catalyst may be heated at differenttemperatures for set periods of time. For example, the catalyst may beheated to 200° C. under a nitrogen gas sweep and help for 6 hours andthen heated to 250° C. and held at 250° C. for four hours. The heatingcycle may be repeated until less than 1 ppm of water or no water isdetected in the catalyst. The temperature of the reactor may be reducedunder the inert atmosphere to a temperature of less than about 150° C.

Temperatures in reactor 110 may range from about 165° C. to about 260°C. or from 190° C. to 210° C. at a pressure ranging from 10 psig to 800psig (from about 0.21 MPa to about 5.5 MPa). Operating pressures greaterthan atmospheric pressure may create a single, continuous liquid phaseof the reagents within reactor 110. Such condition of the fatty acidglycerides and the alcohol aids the kinetics of the process. Thus, thealcohol may be maintained in a liquid state and a higher reaction rateis achieved. Flow of fatty acid glyceride feedstock/alcohol stream 106through reactor 110 may range from about 0.1 WHSV to about 1.0 WHSV,from 0.3 to 0.8 WHSV, or from 0.5 to 0.7 WHSV.

In some embodiments, the process stream is monitored. For example, theabsence or appearance of products may be monitored using near infraredspectrometry. During the continuous process, real-time monitoring of thechanges in the data (for example, changes in the near infrared spectrum)within the process at critical points provides data continuously on therelative concentrations of fatty acid glycerides, glycerides, fatty acidalkyl esters, glycerin and other components. Based on the assessment ofthe monitored relative concentrations, adjustments to process conditionsmay inhibit by-product formation and/or allow production of high qualityfatty acid alkyl esters. Based on the monitored conditions, adjustmentsmay not be necessary.

In some embodiments, data from one or more continuous processes may becollected continuously or at specified intervals and compiled into datasets. Such data sets include a) conversion data for various fatty acidglyceride feedstocks to fatty acid alkyl esters, b) catalyst aging, c)fatty acid glyceride feedstock selection (for example, selection basedon the content of free fatty acid in feed and/or other impurities in thefatty acid glyceride feedstock), d) product quality, both for fatty acidalkyl esters and glycerin, e) purity of recycled alcohol, f) compositionof fatty acid alkyl esters and the fatty acid alkyl esters distillationresidues and g) the quality of final product. Other types of data may becollected, as necessary. Data may be collected from one or more processsteps and compared across locations, time periods and age of facilities,among other factors. The stored data may be compared and conditions maybe adjusted over time based on fatty acid glyceride feedstock and fattyacid glyceride feedstock suppliers, the seasonal variation in renewablefatty acid glyceride feedstocks and other operating parameters. In someembodiments, one or more process conditions at one or more locations areadjusted to maintain or improve the quality of the products produced,based on collected data.

Assessing the collected data continuously and in real-time allowsassessment of small changes in reaction parameters on total systemperformance and to adjust these parameters to produce high quality fattyacid alkyl esters. Collecting data may include sending data to a remoteserver that includes data from the system and other system in a datamanagement system. The data may be compared to other systems andadjustments may be made depending on the assessment of the data. Forexample, based on the data, the flow rate, temperature, pressure, ormole ratio of methanol to total fatty acid glycerides may be adjusted toincrease fatty acid alkyl ester conversion at one or more locations.Additional adjustment points include flow rate, varying pressure andtemperature across an alcohol flash evaporator to achieve alcoholrecycled economics, and flow rate, distillation take over ratio (ratioof the mass of recovered condensate in a distillation to the mass of theundistilled material) and vacuum in short-path distillation to achievehigh quality products. Assessment and adjustment of parameters may lowercosts in producing products, thus making production of bioproductseconomically feasible. In some embodiments, real time monitoringprovides information about the formation of by-products from sidereactions. For example, water content in the reactor may be monitored.Production of an excess amount of water may promote hydrolysis of thefatty acid alkyl ester product to alcohols and fatty acids. Based on theassessment of the water content in the reaction mixture, conditions maybe adjusted to minimize the amount of water produced during the process.

Pressurized crude product stream 112 may exit reactor 110 at desiredflow rate and pressure to maintain continuous operation of reactor 110.For example, crude product stream 112 may exit reactor 110 at atemperature of about 200° C. to about 205° C. and a pressure of about880 psig (about 6.0 MPa). A flow rate of pressurized crude productstream 112 may range from about 0.1 WHSV to about 1.0 WHSV, from 0.3 to0.8 WHSV, or from 0.5 to 0.7 WHSV. Pressurized crude product stream 112flows through one or more pressure reduction devices 114 and one or moreheat exchangers 116. Pressure reduction device 114 rapidly drops thepressure of the pressurized crude product stream 112. For example,pressure reduction device may rapidly drop the pressure of crude productstream 112 to about 5 psig (about 0.034 MPa). Heat exchanger 116maintains the temperature of the pressurized stream at a desiredtemperature (for example, a temperature of about 70° C. to about 80°C.). During the rapid pressure drop of the crude product stream somemethanol and water may be removed from the crude product stream.Pressure reduction device 114 may maintain a desired pressure in thereactor while releasing fluid (for example, volatile components, alcoholand water) from reactor 110.

Under reduced pressure, the crude product stream 118 enters separationunit 120, a pressure of the stream may be rapidly reduced. In someembodiments, separation unit 120 is a separation unit which operatesunder a slight vacuum, that removes components having a boiling point ofless than 100° C. (for example, methanol, ethanol and/or water) to berapidly removed. In some embodiments, separation unit 120 is a flashevaporation unit which operates under a slight vacuum, enabling lowboiling alcohols (for example, methanol and ethanol) and other volatiles(for example, water) to be rapidly removed (flashed). The distilled orflash evaporated components may be collected. An average temperature oflow pressure crude product stream 118 may be less than 100° C. orbetween about 70° C. and about 80° C. at 6.4 psig (0.065 MPa) as thecrude product stream enters separation unit 120. A flow rate of lowpressure crude product stream 118 may be about 146.6 lb/hr (about 66.5kg/hr) or about 0.4 WSHV. Rapid reduction of pressure of crude productstream 118 may be induced by creating a pressure differential inseparation unit 120 by using pump 123. For example, applying vacuum tothe top of separation unit 120 until a pressure of about 0.065 MPa isreached. A sudden drop in pressure may induce rapid distillation(evaporation) of the excess alcohol and water from the crude product.Methanol/water stream 122 may exit separation unit 120 transported toone or more recovery tanks. A portion of methanol/water stream 122(stream 122′) may be mixed with fatty acid glyceride feedstock stream100 and/or alcohol stream 102. Analysis of the methanol/water stream 122may be done (for example, using near infrared spectrometry) to determinethe amount, if any, of glycerin and/or fatty acid alkyl ester in themethanol/water stream. Based on the analysis the methanol/water streammay be subjected to further treatment to recover the glycerin and/orfatty acid and/or increase the amount of methanol in the stream. In someembodiments, the methanol/water stream may be primarily water and thustreated as waste water after distillation of the methanol for recycle to103.

Rapid distillation (for example, flash evaporation) removes the excessalcohol and water under mild thermal conditions. During rapidevaporation, the crude fatty acid alkyl ester undergoes minimal or nothermal degradation during the distillation process. Thus, fewerby-products and a higher quality product are produced as compared toconventional processing to produce fatty acid alkyl esters. During rapidevaporation, the temperature of the crude stream may be increased toassist in rapid evaporation of the alcohol, water, and other volatilesin the crude product stream. Due to the sudden loss of pressure, lowboiling alcohols and water evaporate rapidly (flash) and thereby coolthe residual effluent. The recovered alcohol can be refined in aseparate distillation system for reuse, as needed, in the reactor.

Crude fatty acid ester/glycerin product stream 124 may enter separator126. In separator 126, glycerin stream 128 and crude fatty acid esterstream 130 may be separated from the crude fatty acid ester/glycerinproduct stream 124. For example, a crude fatty acid ester stream may beseparated from a glycerin stream using liquid-liquid centrifugation,gravity-based decantation and dynamic centrifugation or other methodsfamiliar to those skilled in the art. In some embodiments, the fattyacid ester stream is separated from the glycerin stream usinggravity-based, electrostatically enhanced separation techniques.

In some embodiments, separator 126 is an electrostatic separator. Insome embodiments, the crude fatty acid ester/glycerin product stream 124may be analyzed using near infrared spectrometry to determine an amountof water in the stream prior to the stream entering the separator. Thecrude fatty acid ester/glycerin product stream may have a water contentof less than 2 percent by weight. In an electrostatic separator anelectric field (for example, direct current and/or alternating current)may be applied to crude fatty acid ester/glycerin product stream 124 toseparate glycerin from crude fatty acid ester stream 124. The separatedglycerin stream may have a purity of greater than 98% by weight.

Crude fatty acid alkyl ester stream 130 may be further purified to meetproduct specifications. In some embodiments, crude fatty acid alkylester stream 130 is used as is for diesel fuel. As shown in FIG. 1,crude fatty acid alkyl ester stream 130 enters distillation unit 132. Indistillation unit 132, crude fatty acid alkyl ester stream 130 isdistilled to produce fatty acid alkyl ester product stream 134 andbottoms stream 136. Distillation units may include, but is not limitedto, wiped-film evaporator or another short-path distillation unit. Fattyacid alkyl ester product stream 134 may contain substantially fatty acidmethyl ester and, thus be used for biofuel without further treatment.Fatty acid alkyl ester product stream 134 may be light colored,substantially water white or water white. In some embodiments, thedistilled fatty acid alkyl ester product stream is passed through one ormore resin beds to produce a high purity, biodiesel product.

In some embodiments, bottoms stream 136 includes polyunsaturated fattyacid alkyl esters (for example, polyunsaturated fatty acid methylesters). The polyunsaturated fatty acid alkyl acids are derived frompolyunsaturated fatty acids present in the starting feedstock (forexample, feedstock 101 in FIG. 1). Polyunsaturated fatty acid alkylesters may be hydrolyzed to produce high purity polyunsaturated fattyacids (for example, omega 3 fatty acids and omega 6 fatty acids).

In some embodiments, crude fatty acid alkyl ester stream 130 is a fattyacid methyl ester stream. At least a portion of the crude fatty acidalkyl ester stream may be diverted and used to make biolubricants, heattransfer fluids, hydraulic fluids, gear oils or engine oils in aseparate reactor. The ability to make biodiesel and biolubricants at thesame facility without changing the catalyst or significantly alteringthe production equipment reduces operating costs.

As shown in FIG. 2, crude fatty acid methyl ester stream 130 may bemixed with high boiling alcohol stream 140 (for example, alcohol streamhaving a carbon number greater than 6) in mixer 104. Fatty acidglyceride feedstock/alcohol stream 142 may pass through heater 108 toraise the temperature of the stream to a temperature proximate thereaction temperature. For example, heater 108 may raise the temperatureof fatty acid glyceride feedstock/alcohol stream 142 to about 220° C. ata pressure of 1-2 psig (about 0.01 to 0.02 MPa).

Fatty acid glyceride feedstock/alcohol stream 142 may enter reactor 110and flow upward through the reactor. A flow rate of fatty acid glyceridefeedstock/alcohol stream 142 may range from about 0.1 WHSV to about 1.0WHSV, from 0.3 to 0.8 WHSV, or from 0.5 to 0.7 WHSV. Reactor 110 mayinclude over one or more heterogeneous catalysts. In some embodiments,the catalyst is a heterogeneous acidic catalyst. In certain embodiments,the catalyst is a double metal cyanide catalyst. Contact of the feedstreams with the catalyst produces a crude product. The crude productincludes fatty acid alkyl esters, glycerin, water, unreacted glyceridesand excess alcohol. The ester portion of the fatty acid alkyl esters mayhave a carbon number greater than or equal to 5.

Temperatures in reactor 110 may range from about 65° C. to about 260° C.or from 90° C. to 2010° C. at a pressure ranging from 1 psig to 2 psig(from about 0.01 MPa to about 0.014 MPa). In some embodiments,temperatures in reactor 110 may range from about 65° C. to about 200° C.or from 90° C. to 205° C. at a pressure ranging from 1 psig to 2 psig(from about 0.01 to about 0.014 MPa). Continuous flow of fatty acidglyceride feedstock/alcohol stream 142 through reactor 110 may becontrolled to produce a desired amount of crude product in a desiredamount of time. For example, a flow of fatty acid glyceridefeedstock/alcohol stream 142 through reactor 110 ranges from about 0.1WHSV to about 1.0 WHSV, from 0.3 to 0.8 WHSV, or from 0.5 to 0.7 WHSV.Real-time analysis of the feed streams, crude product streams and/ormethanol/water streams as described herein may be performed to assessreaction conditions and/or concentrations of components in the variousstreams so that formation of by-products is minimized.

Crude product stream 114 may exit reactor 110 at a temperature between65° C. and about 200° C. and a pressure of about 1 psig to about 2 psig(about 0.1 MPa to 0.2 MPa). The crude product stream 114 flows throughone or more heat exchangers 116. A flow rate of crude product stream 114may range from about 0.1 WHSV to about 1.0 WHSV, from 0.3 to 0.8 WHSV,or from 0.5 to 0.7 WHSV. Heat exchanger 116 maintains the temperature ofthe reactor effluent stream from about 65° C. to about 220° C.

As crude product stream 146 enters separation unit 120, which is heldunder reduced pressure, 486 mmHg, (0.0.65 MPa), the excess of volatilealcohols may be removed (flashed or distilled depending on the boilingpoint of the alcohol), and leave crude biolubricant.

A temperature of crude product stream may be between about 70° C. andabout 80° C. as the stream enters separation unit 120. A flow rate oflow pressure crude product stream may be about 146.6 lb/hr (about 66.5kg/hr) or about 0.4 WHSV. Rapid reduction of pressure may be induced bycreating a pressure differential in separation unit 120 using pump 123for example, reducing the pressure at the top of separation unit 120 toabout 0.065 MPa. In separation unit 120 a temperature of the reactionmixture may be less than 100° C. at about 0.065 MPa. A sudden drop inpressure may induce rapid distillation (evaporation) of the excessalcohol and water from the crude product. Recovered alcohol stream 122may exit separation unit 120 transported to one or more recovery tanks.A portion of the recovered stream 122 (stream 122′) may be mixed withfatty acid glyceride feedstock stream 130_and/or alcohol stream 140.

Rapid distillation (for example, flash distillation) removes the excessalcohol and water under mild thermal conditions. During rapiddistillation, the crude fatty acid alkyl ester undergoes minimal or nothermal degradation during the distillation process. Thus, fewerby-products and a higher quality product are produced as compared toconventional processing to produce fatty acid alkyl esters. During rapiddistillation, the temperature of the crude fatty acid alkyl ester streammay be increased to assist in rapid evaporation of the alcohol, waterand other volatiles in the crude product stream. Due to the sudden lossof pressure, low boiling alcohols and water evaporate rapidly (flash)and thereby cool the residual effluent. The recovered alcohol may bepurified in a separate distillation system for reuse, as needed, in thereactor.

In some embodiments, the alcohol is not volatile enough to permit flashevaporation in separation unit 120. The excess alcohol in the reactoreffluent stream will be removed by aqueous extraction by means known tothose skilled in the art of liquid-liquid extractions. The resultingcrude high boiling ester may be purified as needed to meet industryspecifications for use as biodegradable lubricant base oils.

Crude fatty acid alkyl ester product stream 148 may enter separator 126.In separator 126, an aqueous stream 128, containing excess alcohol orpolyol and crude fatty acid alkyl ester stream 150 may be separated fromthe crude fatty acid alkyl ester/glycerin (for example, crudebiolubricant) product stream 148 using conventional techniques ofliquid-liquid extraction.

In embodiments when glycerin is present in the crude fatty acid alkylester stream, separator 148 is an electrostatic separator. In anelectrostatic separator an electric field may be applied to crudebiolubricant product stream 148 to separate glycerin from crude fattyacid alkyl ester stream 150. The separated glycerin stream may have apurity of greater than 98% by weight.

Crude fatty acid alkyl ester stream 150 may be further purified to meetASTM or commercial product specifications. Crude fatty acid alkyl esterstream 150 may enter distillation unit 132 (for example, a vacuumdistillation unit). In distillation unit 132, crude fatty acid alkylester (for example, biolubricant) stream 150 is distilled to produce afinished product stream 152 and bottoms stream 154. In some embodiments,fatty acid alkyl ester stream 152 is suitable for use as biolubricants,heat transfer fluids and hydraulic fluids, such as 2-cycle engine oil.In some embodiments, distillation unit 132 and separation unit 126 arethe same unit.

In some embodiments, when making fatty acid alkyl esters in a continuousmanner low amounts of alcohol may be entrained in the final product (forexample, less than 1% of alcohol may remain fatty acid alkylester/glycerin crude product and/or the fatty acid alkyl ester product).Fatty acid alkyl ester product containing alcohol (for example,methanol) may not meet biodiesel or other bioproduct specifications.Thus, further purification steps may be required to obtain a productthat meets biodiesel and/or other product specifications. Furthermore,residual alcohol may permit the retention of moisture in the hydrocarbon(oil) phase) which can promote hydrolysis of the fatty acid alkyl esterto fatty acid and alcohol upon storage.

To remove the alcohol from the reaction mixture to the lowest possiblelevel, the separation unit may include an internal heat exchanger in anupper portion of the separation unit. Incorporation of the heatexchanger may allow for all or substantially all of the alcohol/water tobe removed continuously or substantially continuous from the reactioneffluent mixture. For example, a fatty acid methyl ester product mayhave an alcohol (for example, methanol) content of less than 100 ppm,less than 10 ppm, less than 1 ppm, or less. A temperature of the heatexchanger may be greater than the boiling point of the alcohol and/orwater in the reaction mixture at the operating pressure (for example,greater than 65° C. at about 0.065 MPa (about 486 mm Hg). As thereaction mixture enters the alcohol separation unit, alcohol and/orwater may be removed under vacuum while the higher boiling components(for example, crude fatty acid alkyl ester/glycerin mixture) are cooledby the condenser. The higher boiling components may settle to a bottomportion of the alcohol separation unit and be collected. Collectingfatty acid alkyl ester/glycerin mixture under reduced pressure may allowany entrained alcohol to be removed from the mixture through a degassingprocess. The fatty acid alkyl ester/glycerin mixture may collect in thealcohol separation unit until a desired level of the mixture isobtained. The mixture may then be moved (for example, pumped) to a fattyacid alkyl ester/glycerin separator. In some embodiments, the higherboiling components are pumped directly to a fatty acid alkylester/glycerin separator.

In some embodiments, during collection of the fatty acid alkylester/glycerin mixture, glycerin may separate from the fatty acid alkylester/glycerin mixture. The separated or at least a part of theseparated glycerin may be removed from the separator as a separatestream (for example, the glycerin my settle to a bottom portion of theseparator). In some embodiments, the separated glycerin may include somefatty acid alkyl ester. The separated glycerin may be further treated asdescribed herein to separate fatty acid alkyl ester from the glycerin.

FIG. 3 depicts a schematic of using an alcohol separator in a continuousprocess. As fatty acid glyceride feedstock stream 100 from fatty acidglyceride feedstock storage unit 101 and alcohol stream 102 from alcoholstorage unit 103 flow through mixer 104, the streams are mixed to formfatty acid glyceride feedstock/alcohol stream 106. In some embodiments,fatty acid glyceride feedstock/alcohol stream is an emulsion. Mixer 104may be one or more in-line mixers or other known mixers. In someembodiments, the fatty acid glyceride feedstock and alcohol may bedelivered continuously to the reactor as separate streams. Fatty acidglyceride feedstock/alcohol stream 106 may pass through heater 108 toraise the temperature of the stream to a temperature proximate thereaction temperature. For example, heater 108 may raise the temperatureof fatty acid glyceride feedstock/alcohol stream 106 to about 220° C. ata pressure up to 880 psig (about 6.1 MPa).

Fatty acid glyceride feedstock/alcohol stream 106 may enter reactor 110and flow upward through the reactor. A flow rate of fatty acid glyceridefeedstock/alcohol stream 106 may range from about 0.0.1 WHSV to about1.0 WHSV, from 0.3 to 0.8 WHSV, or from 0.5 to 0.7 WHSV.

The flow rate of fatty acid glyceride feedstock/alcohol stream 106through reactor 110 may be determined based on the assessed amount offatty acid glycerides and/or alcohol in the fatty acid glyceridefeedstock/alcohol stream. In some embodiments, a flow rate of the fattyacid glyceride feedstock/alcohol stream is determined based on apredetermined mole ratio of alcohol to free fatty acid. Reactor 110 mayinclude over one or more heterogeneous catalysts. In some embodiments,the catalyst is a heterogeneous acidic catalyst. Contact of the feedstreams with the catalyst produces a crude product. The crude productincludes fatty acid alkyl esters, glycerin, water, unreacted glyceridesand excess alcohol.

In some embodiments, the catalyst is fixed in the reactor. For example,the reactor may be a fixed bed reactor, a continuously stirred tankreactor, fluidized bed reactor or an ebullating bed reactor. Otherdesigns to allow continuous flow of the fatty acid glyceride feedstockstream, alcohol stream, the fatty acid glyceride feedstock/alcoholstream or mixtures thereof over the catalyst and through the reactor maybe contemplated.

Average Temperature in reactor 110 may range from about 165° C. to about260° C. or from 190° C. to 210° C. at an average pressure ranging from10 psig to 880 psig (from about 0.21 MPa to about 6.1 MPa). In someembodiments, the reactor has an average temperature is 210° C. andaverage pressure of 5.1 MPa. Operating pressures greater thanatmospheric pressure may create high-shear of the fluid in reactor 110.High shear may emulsify the fatty acid glycerides and the alcohol andform a quasi single-phase liquid system. Thus, the alcohol may bemaintained in a liquid state and a higher reaction rate is achieved.Flow of fatty acid glyceride feedstock/alcohol stream 106 throughreactor 110 may range from about 0.1 WHSV to about 1.0 WHSV, from 0.3 to0.8 WHSV, or from 0.5 to 0.7 WHSV.

Pressurized crude product stream 112 may exit reactor 110 at desiredflow rate and pressure to maintain continuous operation of reactor 110.For example, crude product stream 112 may exit reactor 110 at an averagetemperature from about 200° C. to about 205° C. and an average pressurefrom about 10 psig to 880 psig (about 0.21 MPa to about 6.1 MPa). A flowrate of pressurized crude product stream 112 may range from about 0.1WHSV to about 1.0 WHSV, from 0.3 to 0.8 WHSV, or from 0.5 to 0.7 WHSV.Pressurized crude product stream 112 flows through one or more pressurereduction devices 114 and one or more heat exchangers 116. Pressurereduction device 114 rapidly drops the pressure of the pressurized crudeproduct stream 112. For example, pressure reduction device may rapidlydrop the press of pressurized crude product stream 112 to about 5 psig(about 0.034 MPa). Pressure reduction device 114 may maintain a desiredpressure in the reactor while releasing fluid (for example, volatilecomponents, alcohol and water) from reactor 110. In some embodiments,pressure reduction device 114 is a back pressure valve.

Heat exchanger 116 maintains the temperature of the pressurized streamat a desired temperature (for example, a temperature of about 70° C. toabout 80° C.). During the rapid pressure drop of the crude productstream some or a majority of the methanol and water may be removed fromthe crude product stream. In some embodiments, a majority or asubstantial amount of methanol and water may be removed from the crudeproduct stream via conduit 138. In some embodiments, conduit 138 isconnected to an alcohol recovery unit.

As low pressure crude product stream 118 enters alcohol separation unit140, a pressure of the stream may be rapidly reduced. For example, thepressure of the stream may be reduced from an average pressure of 6.1MPa to about 0.065 MPa. A temperature of low pressure crude productstream 118 may be about 70° C. at an average pressure of 486 mmHg (0.065MPa) as the crude product stream enters alcohol separation unit 140. Aflow rate of low pressure crude product stream 118 may be adjusted usingpump 142. Alcohol separation unit 140 includes heat exchanger 146.Cooling fluid may be circulated in heat exchanger 146 (shown by arrows148). The heat exchanger may be maintained at an average temperaturehigher than the boiling point of the alcohol being removed from thealcohol separation unit (for example, greater than 65° C. at 0.065 MPa).Reduction of pressure of crude product stream 118 is induced by creatinga pressure differential in alcohol separation unit 140 using vacuum pump144. For example, using pump 144 to apply vacuum to the top of alcoholseparation unit 140 until a pressure of about 0.04 MPa is reached.

A drop or sudden drop in pressure (for example, pulling a vacuum on thereactor effluent stream) may induce rapid distillation (evaporation) ofthe excess alcohol and water from the crude product. Methanol/waterstream 122 may exit separation unit 140 transported to one or morerecovery tanks. A portion of methanol/water stream 122 (stream 122′) maybe mixed with fatty acid glyceride feedstock stream 100 and/or alcoholstream 102. Analysis of the methanol/water stream 122 may be done (forexample, using near infrared spectrometry) to determine the amount, ifany, of glycerin and/or fatty acid alkyl ester in the methanol/waterstream. Based on the analysis the methanol/water stream may be subjectedto further treatment to recover the glycerin and/or fatty acid and/orincrease the amount of methanol in the stream. In some embodiments, themethanol/water stream may be primarily water and thus treated as wastewater.

Rapid distillation (for example, flash evaporation) removes the excessalcohol and water under mild thermal conditions. During rapiddistillation, the crude fatty acid alkyl ester undergoes minimal or nothermal degradation during the distillation process. Thus, fewerby-products and a higher quality product are produced as compared toconventional processing to produce fatty acid alkyl esters. During rapiddistillation, the temperature of the crude stream may be increased toassist in rapid evaporation of the alcohol, water, and other volatilesin the crude product stream. Due to the sudden loss of pressure, lowboiling alcohols and water evaporate rapidly (flash) and thereby coolthe residual effluent. The recovered alcohol can be refined in aseparate distillation system for reuse, as needed, in the reactor.

As crude product steam 118 contacts the heat exchanger, crude fatty acidalkyl ester/glycerin mixture 124 cools and collects in a bottom portionof alcohol separation unit 140. Collection of the fatty acid alkyl esterand glycerin under reduced pressure may allow the entrained alcohol tobe removed from the crude fatty acid alkyl ester/glycerin mixture 124.Pump 142 may be connected to a level controller (not shown) whichmonitors the level of crude fatty acid alkyl ester/glycerin mixture 124collecting in alcohol separation unit 140. When the level of crude fattyacid alkyl ester/glycerin mixture 124 reaches a desired level asindicated by level controller, pump 142 may engage and move a portion ofcrude fatty acid alkyl ester/glycerin mixture 124 from alcoholseparation unit 140.

Upon standing, glycerin layer 150 may further separate from fatty acidalkyl ester/glycerin mixture 124. If sufficient glycerin separates fromcrude fatty acid alkyl ester/glycerin mixture 124, glycerin stream 152may be removed from alcohol separation unit 140 using pump 154.

Crude fatty acid ester/glycerin product stream 124 may enter separator126. In separator 126, glycerin stream 128 and crude fatty acid esterstream 130 may be separated from the crude fatty acid ester/glycerinproduct stream 124. For example, crude fatty acid ester stream 130 maybe separated from a glycerin stream 128 using a liquid-liquid decanter.In an embodiment, crude fatty acid ester stream 130 may be separatedfrom a glycerin stream 128 using a liquid-liquid decanter in parallelwith an electrostatic precipitator.

In some embodiments, crude fatty acid alkyl ester stream 130 is a fattyacid methyl ester stream. At least a portion of the crude fatty acidalkyl ester stream may be used to make biolubricants, heat transferfluids, or engine oils. The ability to make biodiesel and biolubricantsat the same facility without changing the catalyst or significantlyaltering the production equipment reduces operating costs.

Crude fatty acid alkyl ester stream 130 may be further purified to meetproduct specifications. In some embodiments, crude fatty acid alkylester stream 130 is used as is for diesel fuel. Crude fatty acid alkylester stream 130 enters distillation unit 132. In distillation unit 132,crude fatty acid alkyl ester stream 130 is distilled to produce fattyacid alkyl ester product stream 134 and bottoms stream 136. Distillationunits may include, but is not limited to, wiped-film evaporator oranother short-path distillation unit. Fatty acid alkyl ester productstream 134 may contain substantially fatty acid methyl ester and, thusbe used for biofuel without further treatment. Fatty acid alkyl esterproduct stream 134 may be light colored, substantially water white orwater white. In some embodiments, the distilled fatty acid alkyl esterproduct stream is passed through one or more resin beds to produce ahigh purity, biodiesel product.

In some embodiments, bottoms stream 136 includes polyunsaturated fattyacid alkyl esters (for example, polyunsaturated fatty acid methylesters). The polyunsaturated fatty acid alkyl acids are derived frompolyunsaturated fatty acids present in the starting feedstock (forexample, feedstock 100). Polyunsaturated fatty acid alkyl esters may behydrolyzed to produce high purity polyunsaturated fatty acids (forexample, omega 3 fatty acids and omega 6 fatty acids) as describedherein.

In some embodiments, one or more parameters of the continuous processare controlled using automated controllers, for example, a computer. Themethods described herein may also be embodied on a computer readablemedium and in a controller. One or more controllers may be coupled toone or more mixing devices, one or more reactors, one or more separationdevices, and or one or more distillation devices. The controllers may becoupled to a computer that includes a computer readable medium. Thecomputer readable medium may include the parameters for makingbioproducts using continuous systems. For example, the computer mayinclude storage devices that are accessible by the computer readablemedium. The storage devices may include look-up tables and/or databasesthat include, but are not limited to, data associated with flow rates,molar ratios, temperatures, pressures, fatty acid concentrations in thefeedstock or alcohol molecular weights, fatty acid glyceride molecularweights, or other such data. One or more parameters may be displayed ona controller or a display device coupled to the computer during theoperation of the process.

In some embodiments, each unit of the continuous system may have aninput and an output. For example, inputs may be coupled to a fatty acidglyceride supply unit and/or an alcohol stream supply units and outputscoupled to the reactor. A controller may be coupled to a valve of one ofthe supply units. The mixing device, reactor, distillation units, and/orseparation units are monitored for fluid flowing through them. Whenfluid flow or mass flow is detected through one or more of the units inthe process, the controllers coupled to the valves may send a signalsuch that the valve position is adjusted until flow of fluid through thesystem (for example, the flow of the feedstock stream from a mixingdevice to the reactor, and/or the flow from the reactor to thedistillation unit) meets the desired parameters.

EXAMPLES

Non-limiting examples are described herein.

Example 1—Batch

Palm oil (2.99 kg) and methanol (1.61 kg) were charged to a 20 Lstainless steel vessel. To this was added, with stirring, 0.15 kg ofdouble metal cyanide powdered catalyst (5% by wt.). The vessel wassealed and temperature increased to 170° C. with agitation and held withagitation for eight (8) hrs. Upon cooling and filtration, a total of4.451 kg of material was recovered. Following the distillation of excessmethanol, the fatty acid methyl ester (FAME) and glycerin layers wereseparated, affording 0.316 kg of glycerin (99.5% by wt) and 4.135 kgFAME (99.5% by wt).

Example 2—Batch

A batch reaction for producing fatty acid methyl esters (bio-diesel)from soybean oil and methanol was conducted in a “Teflon-lined” steelautoclave (100 ml) and using a rotating hydrothermal reactor (Hiro Co.,Japan; Mode-KH 02). The rotation speed was 50 rpm. A soybean oil (33grams), methanol and “finely powdered” solid alumina catalyst (5 wt %based on grams of soybean oil, containing 14.9% by weight molybdenumtrioxide and 2% by weight phosphorus) were sealed in a reactor andheated at 190° C. for 8 hours. The alcohol to oil molar ratio was 15:1.The autoclave was cooled to room temperature. The catalyst was separatedby centrifugation followed by simple decantation. The entire liquid wassubjected to vacuum distillation and excess, unused alcohol was removed.Glycerol settled at the bottom as a separate layer. Fatty acid methylesters and un-reacted oil, if any, floated above the glycerol portion.Petroleum ether (20 to 50 ml) was then, added. The esters and oilreadily went into the petroleum ether layer. Glycerol remained as aseparate layer. It was separated and its yield was determined and puritychecked by ¹H nuclear magnetic resonance (Bruker 200 MHz Avance NMRspectrometer). The conversion to fatty acid methyl ester was 100%. Thefatty acid alkyl ester portion contained 95.6% fatty acid methyl ester,0% triglyceride, 0.5% diglyceride, and 4.0% monoglyceride as determinedby high performance liquid chromatography (HPLC).

Example 3—Continuous Process

In a fixed bed reactor (D×ID=3″×24″), a bed of a alumina supportedcatalyst (1,341 g) containing 14.9% by weight molybdenum oxide (MoO₃),2% by weight phosphorus (P), and inert alumina balls (540 g, Denstone®D99, Norpro, Saint Gobain, Ohio, U.S.A.) in a 2.5:1 ratio in the form ofextrudates is placed in a stainless steel reactor having a provision ofauto-controlled temperature and feed-flow facilities. As methanol andfatty acid glyceride feedstock are immiscible, a duel pumping system wasutilized and the feedstock was sent in an upward-flow at a WHSV of 0.7.The mass ratio of methanol to fatty acid glyceride feedstock wasmaintained at 0.54. The operating temperature of the reactor wasmaintained at 216° C. and the pressure of 45 bar. The reactionconditions and mass ratio were maintained over a period of 10 days. Theproduct was collected at the top of the reactor. The entire liquid wassubjected to vacuum distillation and excess, unused alcohol was removed.The crude product was separated from the glycerin in a separatoryfunnel. TABLE 1 lists the fatty acid glyceride feedstock and the crudeproduct analysis.

TABLE 1 Fatty Acid Product composition, wt % by HPLC Glyceride Pressure,Temp., WSHV, Tri- Mono- Fatty acid

bar ° C. hr⁻¹ glycerid Di-glycerid glycerid methyl RBD 45 216 0.7 0.040.03 0.38 99.55 soy oil Corn Oil 45 216 0.7 0.99 0.51 0.49 98.01 DG 45216 0.7 0.69 0.43 0.48 98.40 Cottonseed

indicates data missing or illegible when filedRDB soy oil is refined, bleached and deodorized soy oil. DG Cottonseedis degummed cottonseed oil.

The crude product was distilled in a glass wiped film evaporator toafford water white fatty acid methyl ester with a total fatty acidglycerides value of less than 0.17. The distilled product met the ASTMD6584 specifications for biodiesel.

Continuous.

The production of fatty acid octyl ester (biolubricants) byesterification of a crude fatty acid octyl ester derived from soybeanoil with octanol is described herein. The reaction was conducted in asimilar manner as described in Example 2. Over a period of 2 days soyoil was contacted with an alumina supported catalyst containing 14.12%by weight MoO₃, 1% by weight P, and 1% by weight CaO in the presence ofoctanol at a space velocity of 0.68/hr, temperature of 211° C., pressureof 44 bar and a mass ratio of 0.53 of octanol to soy oil to produce acrude product containing fatty acid octyl ether and glycerin. Thereaction conditions were: The crude fatty acid octyl ester feedstockcontained 98% fatty acid octyl ester and 2% monoglyceride.

Example 5—Continuous

An alumina supported catalyst (21.4 g) containing 14.9% by weight MoO₃and 2.0% by weight P was positioned in a stainless steel fixed bedreactor (1.6 cm×36.5 cm). The crude soy methyl ester mixture fromExample 3 and an excess of 1-octanol (molar ratio of crude soy methylester to octanol of 1:9) was contacted with the molybdenum catalyst atspace velocities between of 0.4/hr and 0.75/hr temperature of 200° C.and a pressure of 1 atm. About 99.7% of the fatty acid methyl ester wasconverted to the octyl ester, as analyzed by HPLC. Methanol and theoctyl esters were recovered by distillation.

Example 6—Continuous

An alumina supported catalyst (11.4 g) containing 14.9% by weight MoO₃and 2.0% by weight P was positioned in a stainless steel fixed bedreactor (1.6 cm×36.5 cm). Crude sunflower methyl ester mixture wascontacted with the catalyst in the presence of 2-ethyl-1-hexanol or1-octanol a space velocity of 0.4/hr and 1 atm to produce thecorresponding fatty acid alkyl esters. TABLE 2 lists the degree ofconversion at varying temperatures.

TABLE 2 Alcohol Temp (° C.) Ester Yield (%) Mass Balance (%) 1-Octanol230 90.3 87.9 1-Octanol 230 93.5 97.8 2-Ethyl-1-hexanol 230 93.5 97.82-Ethyl-1-hexanol 240 93.3 97.7 2-Ethyl-1-hexanol 250 92.5 97.4

Continuous.

A tubular reactor with five sagitally positioned thermowells wasequipped with thermocouples to measure temperatures throughout thelength of catalyst bed. Mass flow meters were installed in-line tomeasure mass flow rates into the reactor for both feedstock and methanoland from the reactor and to adjust the mass ratios to control theprocess. The catalyst bed was formed by filling the space (0.304 mID×2.134 mL) with 90.7 kg catalyst and a layer of inert alumina ballsabove (5.71 kg) and below (5.71 kg) the catalyst bed, the alumina ballsserving as a support for the catalyst bed and space filling to reducereactor void volume and to increase reagent and effluent flow ratesthrough the reactor. These inert alumina balls had no catalyticproperties under the process conditions described herein.

The feedstock was pumped into the reactor from the bottom of the reactorto the top of the reactor (upflow mode). The catalyst included about 15%by weight MoO₃, 3% by weight P, and 1% by weight CaO supported onalumina. The catalyst was prepared as described herein and in U.S. Pat.No. 8,124,801 to Srinivas et al.

The catalyst was activated by introducing a heated stream of drynitrogen gas into the contacting zones at a space velocity of 500/hr(SV=vol N₂/hr divided by vol of catalyst) at atmospheric pressure. Thetemperature was increased from ambient temperature to 200° C. in thecontacting zone (catalyst bed) at a rate of 50° C./hr and then held at200° C. for 6 hrs. Following this holding period, the temperature wasraised again to 25° C. at a rate of 50° C./hr and then held there for anadditional 4 hrs. At the conclusion of this last holding period the flowrate of nitrogen was reduced to a space velocity of 5/hr and thecatalyst bed permitted to cool to that start-up temperature of 150° C.

The crude feedstock (see, TABLE 3 for properties of feedstock) and themethanol (methanol, 99.95% purity) were pumped through an in-line staticmixer and inline heater into the reactor.

The reactor pre-heater raised the temperature of the reagents to within10° C. of the preferred reactor temperature. The reagent mixture flowedupwards through the contacting zone and out of the top of the reactor.

Normal contacting conditions were as follows: WHSV of 0.4 h⁻¹(WHSV=0.4/hr, where WHSV=wt of oil/hr divided by wt of catalyst), anaverage temperature across the contacting zone ranged between 200-210°C., pressure of 46-55 bar and a molar ratio of methanol to feedstock inthe range of 12 to 15:1. These operating conditions were controlled by aprogrammed logic system, which was designed to hold these parameterswithin a range of +/−3% of set point.

A total of 957.6 kg of feedstock was processed over a 24 hr period atthe a WHSV of 0.45/hr, average catalyst bed temperature of 210° C.,pressure of 47 bar and a molar ratio of 12:1. Upon exiting the reactor,the reactor pressure was reduced through a back pressure valve to 1-2bar and the methanol, which flash evaporated, was recovered for recycle.The total raw/crude product was analyzed periodically after the methanolflash and conversion of corn oil into fatty acid methyl esters was 99.5%as determined by gas chromatography analysis using ASTM method D6584.

A total product exited the reactor (that is, crude product consisting offatty acid methyl esters and some unreacted glycerides, water, methanoland glycerin) and passed through a high-pressure separator. In thehigh-pressure separator, a vacuum of 250-350 mmHg was applied at 100° C.to evaporate a significant portion of the methanol and water from thetotal product (95+% of methanol). This methanol and water vapor mixtureare condensed elsewhere and stored for later refinement of the methanol.

The crude fatty acid alkyl ester/glycerin stream was introduced into anelectrostatically enhanced gravity separator. In the electrostaticseparator, the glycerin stream and the crude fatty acid methyl esterstream were separated continuously. Each separated phase was pumped torespective holding tanks. Separating conditions in the electrostaticprecipitator were nominally: input voltage: 480 V, single phase, at 10.4amp, secondary voltage: 23 kV, single phase at 217 amp, tertiaryvoltage: 100 V at 2 amp.

The crude fatty acid alkyl ester stream was purified using a short-pathdistillation system operating at between 24-30 mmHg with a jackettemperature of 200° C. to yield a clear, colorless, bright liquid. Thedistilled product was routinely analyzed by GC, HPLC and NIR todetermine the purity of the distilled product and specification graderelative to ASTM standards. Crude product and distilled productcomposition and properties are summarized in Table 2. The distilledproducts met the ASTM specifications (ASTM Method D6751) for biodiesel.

The glycerin recovered from the electrostatic separator was assayed tobe 93-97% pure within minor impurities only, methanol and water.Variations in crude glycerin composition are due to variations in theprocess. No further refinement of the glycerin was carried out in theseExamples, as methods for glycerin refinement are known. Otherembodiments of this general process may include vacuum distillation ofthe glycerin to achieve higher commercial grades.

Methanol recovered from the Flash apparatus is recycled through adistillation system with column employing a structured packing, avariable reflux ratio and a forced reboiler. The methanol recycle in thefashion afforded 99.5% recovery of unreacted methanol at a purity of99.9% methanol and 0.1% water.

TABLE 4 lists the operating conditions, feed stock conversions,biodiesel yield, and glycerin yield for RBD soy oil, degummed soy, cornoil, poultry fat, bleachable fancy tallow, a yellow grease-soy blend, a70:30 blend of degummed soy oil and pure oleic acid and the distillationbottoms using the process described in Example 7. The molar ratio wasbased on the original weight of triglyceride imputed to this sample ofdistillation bottoms.

In this patent, certain U.S. patents and U.S. patent applications havebeen incorporated by reference. The text of such U.S. patents and U.S.patent applications materials is, however, only incorporated byreference to the extent that no conflict exists between such text andthe other statements and drawings set forth herein. In the event of suchconflict, then any such conflicting text in such incorporated byreference U.S. patents and U.S. patent applications is specifically notincorporated by reference in this patent.

Further modifications and alternative embodiments of various aspects ofthe invention may be apparent to those skilled in the art in view ofthis description. Accordingly, this description is to be construed asillustrative only and is for the purpose of teaching those skilled inthe art the general manner of carrying out the invention. It is to beunderstood that the forms of the invention shown and described hereinare to be taken as the presently preferred embodiments. Elements andmaterials may be substituted for those illustrated and described herein,parts and processes may be reversed, and certain features of theinvention may be utilized independently, all as would be apparent to oneskilled in the art after having the benefit of this description of theinvention. Changes may be made in the elements described herein withoutdeparting from the spirit and scope of the invention as described in thefollowing claims. In addition, it is to be understood that featuresdescribed herein independently may, in certain embodiments, be combined.

TABLE 3 Moisture Free Fatty Unsapon- (wt %) Acid (wt %) ifiablesFeedstock (AOCS Ca 2e-84) (ASTM D664, B) (AOCS 6b-53) RED Soy Oil 0.100.15 0.42 (food grade) Degummed Soy 0.08 0.15 0.50 Oil Corn Oil from0.18 10.1 0.71 EtOH DDGS* Corn Oil from 0.19 12.24 0.65 EtOH DDGSPoultry Fat 0.13 3.85 1.74 Bleachable 0.19 1.86 2.18 Fancy Tallow YellowGrease 0.23 7.11 0.41 *DDGS refers to Distillers' dried grains andsolubles.

TABLE 4 Operating Conditions Temp Press WHSV Molar Ratio FeedstockBiodiesel Yield Example Feedstock (° C.)

(hr⁻¹) MeOH:feedstock Conv. (%) I.A RBD Soy Oil 200 47 0.4 15 99.9 99.71.B Degummed Soy Oil 185 54 0.5 15 97.5 99.0 1.C Corn Oil 185 43 0.5 1598.4 99.4 1.D Poultry Fat 210 47 0.6  9 93.4 99.7 1.E Bleachable FancyTallow 199 39 0.45  9 95.9 99.5 1.F Yellow Grease (1:1, w/w) 190 37 0.415 96.0 99.1 1.G Deg. Soy/Oleic acid (7:3, w/w) 180 28 0.4 15 (soy); 8(OA) 97.1 99.8 2.A Distillation Bottoms 170 28 0.4  9 98.3 99.1

indicates data missing or illegible when filed

1-117. (canceled)
 118. A method of continuous manufacture of a fattyacid C₅-C₅₀ alcohol ester comprising contacting a fatty acid methylester feedstock stream with a C₅-C₅₀ alcohol stream and with ahexavalent molybdenum catalyst to produce a reaction mixture streamcomprising a fatty acid C₅-C₅₀ alcohol ester.
 119. The method of claim118 wherein the hexavalent molybdenum catalyst comprises molybdenumtrioxide.
 120. The method of claim 118 wherein the hexavalent molybdenumcatalyst is present in an amount in the range of about 5% to about 20%by weight.
 121. The method of claim 118 further comprising a promoter.122. The method of claim 121 wherein the promoter comprises one or moreelements from Group VIB of a periodic table.
 123. The method of claim121 wherein the promoter is present in an amount in the range of about0.1% to about 0.7% by weight of the catalyst.
 124. The method of claim118 further comprising a co-promoter.
 125. The method of claim 124wherein the co-promoter comprises one or more elements from Group IA,Group IIA, Group IIIB, or Group VIII of a periodic table, or mixturesthereof.
 126. The method of claim 124 wherein the co-promoter is presentin an amount in the range of about 0.0001% to about 10% by weight of thecatalyst.
 127. The method of claim 118 wherein the catalyst, promoter,co-promoter, or mixture thereof is supported by a solid supportcomprising a refractory metal oxide wherein the metal comprises a memberof Group IIIA of a periodic table.
 128. The method of claim 118 whereinthe surface area of the catalyst comprises a range between 50 m²/g to300 m²/g.
 129. The method of claim 118 wherein the catalyst comprises apore volume ranging from 0.2 ml/g to 0.95 ml/g.
 130. The method of claim118 wherein the catalyst is calcined at a temperature in the range ofabout 100° C. to about 600° C. for a time ranging from 0.5 hours to 48hours.
 131. The method of claim 118 further comprising a double metalcyanide catalyst.
 132. The method of claim 118 wherein the fatty acidmethyl ester feedstock is pre-incubated with a C₅-C₅₀ alcohol prior tothe addition of the catalyst.
 133. The method of claim 118 wherein thecatalyst is pre-activated by heating or drying prior to contacting thefatty acid methyl ester feedstock stream and the C₅-C₅₀ alcohol stream.134. The method of claim 118 wherein a reaction temperature comprises arange of about 165° C. to about 260° C. and wherein a reaction pressurecomprises about 0.21 MPa to about 5.5 MPa.
 135. The method of claim 118further comprising flash distilling the fatty acid C₅-C₅₀ alcohol esterreaction mixture stream to separate one or more distillates from theC₅-C₅₀ alcohol ester reaction mixture stream.
 136. The method of claim118 further comprising electrostatically separating the fatty acidC₅-C₅₀ alcohol ester reaction mixture stream to separate one or moredistillates from the C₅-C₅₀ alcohol ester reaction mixture stream. 137.The method of claim 118 wherein the hexavalent molybdenum catalystcomprises a fixed bed catalyst.